末制导雷达检测接口标准化初探

分析现役反舰导弹末制导雷达检测接口现状及存在问题的基础上,提出了末制导雷达检测接口标准化思想,并设计了一种能够覆盖我海军所有现役反舰导弹末制导雷达检测接口而且可扩展的末制导雷达标准检测接口。     

Long-period meteor radar temperature variations over Collm (51°N, 13°E) and Kazan (56°N, 49°E)

We have estimated temperatures from meteor radar measurements using the gradient method and the full width at half maximum method over Kazan (56°N 49°E) and Collm (51°N, 13°E). The time series cover the period 2016–2019. The temperature gradient model is constructed from SABER temperature observations. We demonstrate that annual mean, amplitudes and phases of the annual and semiannual oscillations of the radar temperatures are close to those of the MLS and SABER temperatures. The annual mean temperatures over Kazan and Collm differ non-significantly. The seasonal variability of the radar temperature is mostly due to the annual cycle which tends to grow with latitude. The gradient method produces temperatures which agree with the SABER temperatures better than with the MLS ones. The harmonics of the annual oscillations from periods of 73 days up to periods of about 40 days are the most significant day-to-day temperature oscillations and have zonal wavenumber zero. Their periods and phases are in good correspondence with those of the MLS and SABER ones. We also show some results which demonstrate that at 56°N the FWHM method is not as robust as the gradient method.     

敏捷SAR卫星平台载荷一体化控制方法研究

面向具备波束指向捷变能力的小型化敏捷合成孔径雷达(SAR)卫星成像需求,提出了通过平台姿态敏捷机动和载荷波束捷变扫描一体化控制实现条带成像、多条带拼接成像、滑动聚束成像等传统成像模式的方法。针对配合成像过程提出的大角度机动和高精度高稳定度连续指向跟踪控制要求,采用5个单框架控制力矩陀螺(SGCMG)组成的五面锥构形控制力矩陀螺群作为执行机构,设计了基于姿态四元数和角速度反馈的改进型递阶饱和控制器,实现了平台的敏捷机动和对目标的稳定跟踪指向。数学仿真结果表明:该控制系统有效可行。     

Moving target localization in distributed MIMO radar with transmitter and receiver location uncertainties

In this paper, the problem of moving target localization from Bistatic Range(BR) and Bistatic Range Rate(BRR) measurements in a Multiple-Input Multiple-Output(MIMO) radar system having widely separated antennas is investigated. We consider a practically motivated scenario,where the accurate knowledge of transmitter and receiver locations is not known and only the nominal values are available for processing. With the transmitter and receiver location uncertainties,which are usually neglected in MIMO radar systems by prior studies, taken into account in the measurement model, we develop a novel algebraic solution to reduce the estimation error for moving target localization. The proposed algorithm is based on the pseudolinear set of equations and two-step weighted least squares estimation. The Cramer-Rao Lower Bound(CRLB) is derived in the presence of transmitter and receiver location uncertainties. Theoretical accuracy analysis demonstrates that the proposed solution attains the CRLB, and numerical examples show that the proposed solution achieves significant performance improvement over the existing algorithms.     

Simultaneous observations of spread F irregularities over Southeast Asia longitude using Sanya VHF radar,GPS and C/NOFS

Through concurrently measurements by Communication/Navigation Outage Forecasting System (C/NOFS), Sanya VHF radar and GPS ionospheric scintillation receiver on 12 March 2010, five plasma bubbles were found and three of them were observed by all those instruments. Two well-developed plumes with strong backscatter echoes were measured by Sanya radar and their corresponding depletions were observed by C/NOFS in Orbit 10317, 10318 and 10319. Broad plasma depletions resulting from merging process were found in orbit of 10318. The occurrence time and geophysical positions of scintillations correlate well with observations implemented by Sanya VHF radar and C/NOFS. Observations from three types of instrument indicate that the spread F irregularities have distinct scale. There were longitudinal differences between Sanya VHF radar and C/NOFS as irregularities measured, and the eastward drift of developed bubbles are responsible for these differences.     

基于离散伴随方程的三维雷达散射截面几何敏感度计算

针对有限差分法计算雷达散射截面（RCS）梯度效率低,采用高精度雷达散射截面评估时计算代价高的问题,提出了一种基于麦克斯韦积分方程离散伴随方程的RCS梯度高效计算方法。基于伴随方程的梯度计算可以通过一次雷达散射截面求解、一次伴随方程求解获得RCS关于所有设计变量的梯度。其中麦克斯韦积分方程离散伴随方程的形式与原方程基本一致,可以采用矩量法（MOM）及多层快速多极子算法（MLFMA）求解。伴随方程求解计算量与直接雷达散射截面评估基本一致,存储量在直接雷达散射截面评估的基础上增加不明显。通过双椎体模型、导弹模型对基于矩量法、多层快速多极子算法的伴随梯度进行验证,证明了基于伴随方法的RCS梯度计算可以实现复杂外形中RCS梯度的高效、高精度求解,为基于梯度的高精度气动/隐身一体化优化提供了基础。     

Some features of the day-to-day MLT wind variability in winter 2017–2018 as seen with a European/Siberian meteor radar network

We present results of wind measurements near the mesopause carried out with meteor radars (MRs) at Collm (51°N, 13°E), Obninsk (55°N, 37°E), Kazan (56°N, 49°E), Angarsk (52°N, 104°E) and Anadyr (65°N, 178°E) from October 1, 2017 till March 31, 2018. The Collm and Kazan MRs are SKiYMET radars with vertical transmission and radio echo height finding, while the other radars operate with horizontal transmission and without height finding. We paid particular attention to the meridional wind variability with periods of 4–6 days and 9–11 days. The waves with these periods are seen as spots of the wave activity in the wavelet spectra and include oscillations with different periods and different discrete zonal wavenumbers. These wave packets successively propagate as a group of waves from one site to another one in such a way that they are observed at one site and almost disappear at the previous one. The 4–6 wave group includes planetary-scale oscillations (individual spectral components) which have eastward phase velocities and mostly zonal wavenumbers 2 and 3, and the vertical wavelength exceeds 70 km at middle latitudes. The source of the oscillations is the polar jet instability. The wave group itself propagates westward, and the amplitudes of wind oscillations are approximately 5–6 m/s as obtained from the wind data averaged over the meteor zone. The 9–11 day wave set propagates westward as a group and mainly consists of spectral components which have westward phase velocity and zonal wavenumber 1. Amplitudes of these wind perturbations strongly vary from station to station and can reach, approximately, 8 m/s. The vertical wavenumber is 0.014 km⁻¹ as taken from the Kazan and 0.05 km⁻¹ according to the Collm data. We obtained a global view on the waves by using the AURA MLS geopotential data. We found a good correspondence between wave features obtained from the MR wind measurements and the MLS data. To our knowledge, such a wave propagation of planetary wave in the mesosphere/lower thermosphere (MLT) region has so far not obtained much attention.     

SAR卫星用能量功率兼顾型锂离子电池研究

未来大功率合成孔径雷达(SAR)卫星的发展对储能电池组提出了轻量化、倍率高及在轨寿命长等要求,而现有的SAR卫星用功率型锂离子电池产品已无法满足未来需求。通过优化正极材料和电池设计,加入功能电解液,在保证电池功率特性的同时,显著提升了电池的能量密度和循环稳定性。本文研制出的新一代能量功率兼顾型锂离子蓄电池,额定容量为25.0 Ah,初期放电比能量达到180.0 Wh·kg~(-1),2 C放电容量为0.2 C容量的91.0%,1 C-100%放电深度(DOD)和2 C-30%DOD循环性能优异,可以满足下一代大功率SAR卫星的供配电需求,且大幅降低了电源系统重量,提高了卫星储能系统的利用率和平台有效载荷能力。     

机载220 GHz云雷达衰减订正模拟试验

针对220 GHz云雷达回波信号的衰减问题,结合典型云滴谱和云参数,对水云和冰云模拟取样2 100次,应用离散偶极子近似法计算了220 GHz云雷达探测云滴粒子的衰减系数kc和雷达反射率因子Z的关系。在考虑大气和云对220 GHz云雷达信号衰减的基础上,对水云和冰云的机载220 GHz雷达回波强度进行了数值模拟,根据得到的kc-Z关系,进行衰减订正的模拟试验。结果表明:水滴云比冰晶云的衰减系数大2~3个数量级;相对于小粒子的水云和冰云,大气吸收是造成机载220 GHz云雷达衰减的主要原因。高频段的雷达信号在传播路径上的衰减非常明显,本研究中给出的kc-Z关系适用于220 GHz频率雷达的云衰减订正计算。     

天籁射电阵的空间碎片探测性能分析

提出以曲靖非相干散射雷达作为一种可能的发射源与天籁射电阵组成一套双基地雷达空间碎片探测系统,对该系统的空间碎片探测性能进行计算与仿真分析,包括可探测目标雷达散射截面积(RCS)、天籁射电阵对空间目标与碎片探测时间、探测效率等。分析表明,该系统具有探测直径10 cm以下级空间小碎片的潜力,并在最后提出了一种基于该系统的交叉波束的确定方法及对空间碎片定位的方法。